224 



A CONTINUOUS RECORD OF ATMOSPHERIC NUCLEATION. 



These data have been plotted in chart 51, the nucleations (n per cubic 

 centimeter) being again laid off in thousands. Both the similarity and the diver- 

 gences of the results of 1902-03 and 1903-04 become apparent at a glance. It 

 has been possible to connect the successive mean data with a curve almost at 

 once without resorting to much smoothing, except in the summer observations 

 of 1903, where the dotted line is drawn to eliminate the probable and excessive 

 rain effect, as well as the effect due to building operations on the college campus, 

 etc. It should be noticed that the new data for 1904 (August, September, 

 October) fall very closely upon the curve for 1903 prolonged. As stated above, 

 § 3, the results from October, 1902, to March, 1903, are reduced from the old 

 scale and are not at once comparable in absolute magnitude with the remaining 

 data, but the relations are nevertheless well indicated. 



Oct J^. Slecr. JoAv. ftir Aa/r Jlfrr Aai^. Jvm, Juhj Qn^. ^tpt Oct. Mo 



Chart 51. — Mean Monthly Nucleations (Ordinates) from October, 1902, to Octobrr, 1904, 

 IN Thousands per Cub. Cf.ntim. 



37. Occurrence of maxima and minima of nucleation during the winter and 

 the summer solstices, respectively. — The remarkable result of both curves is un- 

 mistakable : remembering that the mean micleations hold for the middle of the 

 month, the maxima of nucleation both in 1902 and 1903 occurred between the 

 middle of December and the middle of January, nearer the latter; in other 

 words, about at the time of the winter solstice. The minima for summer occur 

 between the middle of June and the middle of Augttst somewhat after the 

 summer solstice. The winter maximum is in both cases sharply indicated and 



